Scale.



A. B. CLARDY.

SCALE.

APPLICATION FILED ocT. I8. 1916.

Patented sepi. 17,1918.

Afro/Mfrs UNITED' 'STATES ALBERT BASIL CLARCDY,

PATENT carrer.

F BALBOA, CANAL ZONE. I

SCALE.

To all whom t may concern.'

Be it known that I, ALBERT B. CLARDY,l 8.4

' citizen of the United States', and a'resident of Balboa, in the 'Canal Zone, have invented tion `and arrangement of parts a new and Improved Scale, `of which the following is afull, clear, and eXact description. My invention relates to a'combinatlon of scales particularly adaptable for use by sheet-metal workers in the development of different shaped patterns.

An object of the invention is to provide a straight-edged ruler having various scales thereon whereby the various computations necessary inthe execution of work in sheet metal is considerably simplied and carried y out more rapidly.

A further object of the invention 1s to provide a ruler of the class described with which various patterns may be laid out'with the least amount of computation and, therefore, with less possibility of mistakes.

With the above and vother'ol jects in" view, the nature of which will more fully appear as the description proceeds, the invention consists in the novel construction, combinaas herein fully described, illustrated. and claimed.

In the accompanying drawings, part of the application, similar characters of reference indicate corresponding parts in all the views.

Figure l is a face elevation of a ruler embodying my invention;

Fig. 2 is .an elevation of the otherface of the ruler; and Figs. 3 and 4 are diagrammatic views illustrating a particular use'of the ruler.

Referring to the drawings, the body of the ruler is preferably `of metal with -parallel longitudinal edges 5 and 6. A scale 7 located on one face of the ruler at the edge 5 is for use in measuring oli' the circumference of given diameters without the necessity of multiplying the diameters by the constant ratio 3.1416. For example, the length of the circumference of a 2-.2 inch diameter is obtained by taking on the said scale 7 24, that is, measuring from the 2 to the right of the zero up to -l to the left of the zero, we will have the length of the circumference the diameter of which is 2l inches.

The scale 8 on the same face at the edge 6 is in reality a number of scales of different lengths each presenting siX divisions, and the most frequent use of these scales-is to divide a semicircumference into six equal forming specicatiori pfizetters Patent.' PatetedSept-Q. 17,1918. Application filedoctube'r is, 1ere. seria1 No.-1`26,'239.

parts (s'ee Fig. 3); in which case the semiequal circumference A is divided into' six parts by'means of any of the scales 8 by drawing tangents to the circumference at the diameter a-b of the simicircumference and by placing 1anyof the scales'8 so that the extreme'points od of any of those scales lie on the tangent lines previously mentioned, the points c d being indicated. The intermediate divisions of the scale 8 between the points c d will give the points through which lines parallel to the tangent lines could be drawn, cumference into six equal parts,as clearly shown in said Fig. 3.

The other'face of the ruler has scales 9 at the edge 5 which are tordivide a circum- 1ference into 8 equal parts. The operation of this scaleis in the manner as described with reference to scale 8; -A similar sca-le 9 is pro-4 vided on the same face at the edge 6. The

and Which will divide the semicir.

same face carries also a scale 10 at the edge ably placed on the face which carries the scales 9 and l0, and the said scale 11 is located between the edges 5 and 6 substantially in the middle of the face. This scale carries divisions so related to the total length of the scale. that any desired fraction ofa 90O angle may be constructed by means of said scale, o-e is the base line With which a line o-f is to form anangle of 9. From o as a center draw a line o e, representing the lengthof the scale l1, then from the point e intersect the arce f with a length measured from the point 0 to 10 on the scale ll and draw throughthe said intersection the line 0-f from the point 0. If, for example, it is desirable to construct an angle of, say, 42%o from the base line, this is done by the use of the scale 1l in the following manner: The length of the scale from o to 3'plus that of o to 4` minus that of o to 9 will give 42%", for 0 to`3 represents an angle of 30 and o to 4 represents an angle of 224 therefore be 52%", o to 9 represents 10, and the difference therefore is equal to 425-". The divisions on the scale l1 are obtained in the following manner: The'dcsired fractional as follows: Let us assume that andthe sum will angles of 90 arevdraWn 'and arcs are struck the pipe being three inches y developed.

I' The lines parallel to g-h,

sions of the arcy A and included between thek cumference A,

' with the radius equal to the length of the scale 11. The chords sustaining. said arcs are then laid off from the zero point of said scale and marked with the number which would represent the fraction of the angle of- 90O which the said marked chord sustains.

rEhe scale 11 is particularly useful for laying out 90 elbows in the following manner:

-Let us suppose that an elbow of 90 in ten.

the diameter of and the radius of the elbow through the center of the pipe, twelve inches. Since there are ten sections,

sections is to be developed,

'one Section will be included within the angle On the of9", which is shown in Fig. 3. lines o-e and o-f from the point 0 lay off a length of 12 inches, which is the radius of the elbow, indicated by the'points g' h. By joining the'points the line g-h is formed, which is the central line of the section to be On this line must lie, therefore, the center of the section, which is indicated by the letter i on the line 1f-b which serves as a diameter for the semicircumference A. The varying widths of a section 'are found by dividinglthe circumference into a number of equalv parts in a mannerpreviously described.

from the diviangle e-o-f will give the limiting widths of sections included between said lines. By

layingof the length of thosel lines in the proper sequence on the line m-Q which rep# resents the length ofthe circumference of the pipe, divided according to thesemici'n See Fig. 4, a complete section is developed. If g-h is the joint line it will also be the center line of the section y.

By laying of the lines found to each side of lg--r-al in Fig. 3,

tion is determined. The proper lines in Fig.

l are indicated by corresponding letters 'in Fig. 3, wherefrom the development of the section can be easily followed. s

It will be noted that the scales 5, 6, and

'n 11 have been used to develop a section'of 4an elbow. In place of the scale 8 the scale 9 or 10 might have been used. In certain cases, only two of the three mentioned scales are used; in other cases, only one maybe used; but in complicated workr of the class mentioned the combination formed by the three Scales isnemployed. It will thereforebe seen thatby means of my scales the development lof an ordinary complicated pattern is convsiderablyV simplified, with little possibility of mistake, and the work is considerably expedited and rendered mo'recertain.'`

Iclaim:A ,n Ina rule of the class described, a scale having divisions reading from a common f reference point, said4 divisions being so related to the full scalelength that if'an arc is struck from a point on a straight line wit the fullscalelength as agradius and so as to'intersect said line and then a second arc is struck I`from the intersection of the first arc with the straight line,

equal to the distance from a selected division 'mark to the reference point and so as to inand with a radius tersect the Asaid first arc and a line is'draw'nvv through said the first mentioned point on the straight line an an le is formed which forms that frac# tion o a angle which is indicated by the division used for intersecting the first mentioned arc.

ALBERT. BASIL 'oLARDr last mentioned; intersection to 

